The Tekin handles 5s like a champ with the use of a 35V 1000mfd low ESR capacitor to replace the stock 25v capacitor. I ran all day on Saturday with the R1Pro in my XB8 on 5s and never saw a glitch. Super smooth throttle controll on the Tekin. Dare I say even smoother feeling than the Quark.
But yea... the lack of the hotwire usb device really is annoying. I am running the external LVC for the time being.